These modules go between the factory GM ignition module and coil packs. They have color coded wires that connect to the DIS wiring and are molded using Arathane Polyurethane for it's high dilectric strength and connect directly to the factory terminals. For the 1995-1997 2.2L these are needed to use the MSD coils packs. Also, these interface modules are needed on the 1998-02 2.2L OHV if you will be using the MSD Dis 2 box. This will not work with the 2.4 or ecotec.